U.S. patent number 10,006,366 [Application Number 14/697,880] was granted by the patent office on 2018-06-26 for fuel recirculation thermal management system.
This patent grant is currently assigned to UNITED TECHNOLOGIES CORPORATION. The grantee listed for this patent is United Technologies Corporation. Invention is credited to Simon Pickford.
United States Patent |
10,006,366 |
Pickford |
June 26, 2018 |
Fuel recirculation thermal management system
Abstract
The present disclosure provides systems and methods related to
thermal management systems for gas turbine engines. For example, a
thermal management system comprises a fuel circuit, comprising a
burn line and a recirculation line, and a burn line fuel-oil
cooler, coupled to the burn line and an oil circuit. The oil
circuit comprises a sending portion, configured to carry oil from
the burn line fuel-oil cooler to an engine lube system, and a
returning portion, configured to carry oil from the engine lube
system to the burn line fuel-oil cooler. The thermal management
system further comprises a recirculation fuel-oil cooler, coupled
to the recirculation line and the returning portion, and an
air-fuel cooler coupled to the recirculation line.
Inventors: |
Pickford; Simon (South
Glastonbury, CT) |
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Hartford |
CT |
US |
|
|
Assignee: |
UNITED TECHNOLOGIES CORPORATION
(Farmington, CT)
|
Family
ID: |
58098244 |
Appl.
No.: |
14/697,880 |
Filed: |
April 28, 2015 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170058774 A1 |
Mar 2, 2017 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F
27/02 (20130101); F02C 7/224 (20130101); F02C
7/16 (20130101); F02C 9/32 (20130101); Y02T
50/60 (20130101); Y02T 50/675 (20130101) |
Current International
Class: |
F02C
7/16 (20060101); F28F 27/02 (20060101); F02C
7/224 (20060101); F02C 9/32 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Davis; Mary A
Attorney, Agent or Firm: Snell & Wilmer L.L.P.
Government Interests
GOVERNMENT LICENSE RIGHTS
This disclosure was made with Government support under Contract No.
FA8650-09-D-2923-AETD awarded by the United States Air Force. The
U.S. Government has certain rights in the disclosure.
Claims
What is claimed is:
1. A thermal management system, comprising: a fuel circuit,
comprising a burn line and a recirculation line; a burn line
fuel-oil cooler, coupled to the burn line and an oil circuit,
comprising: a sending portion, configured to carry oil from the
burn line fuel-oil cooler to an engine lube system; and a returning
portion, configured to carry oil from the engine lube system to the
burn line fuel-oil cooler; a recirculation fuel-oil cooler, coupled
to the recirculation line and the returning portion; an air-fuel
cooler coupled to the recirculation line; and a fuel throttle valve
disposed on the fuel circuit and configured to adjustably
communicate fuel from the burn line into the recirculation line;
wherein the fuel circuit is configured to carry fuel from a fuel
feed tank, through the burn line, and to the fuel throttle valve,
at which a first portion of fuel is directed through the burn line
and a second portion of fuel is optionally directed through the
recirculation line, returning to the fuel feed tank; and wherein
the returning portion comprises: a cooling line, coupled to, and
configured to carry oil through, the recirculation fuel-oil cooler
towards the burn line fuel-oil cooler; and a bypass line,
configured to carry oil towards the burn line fuel-oil cooler,
substantially in parallel with the cooling line, and externally of
the recirculation fuel-oil cooler.
2. The thermal management system of claim 1, further comprising: a
first sensor, disposed on the oil circuit downstream of the burn
line fuel-oil cooler and upstream of the recirculation fuel-oil
cooler; and a second sensor, disposed on the burn line downstream
of the fuel throttle valve.
3. The thermal management system of claim 2, wherein an integrated
heat exchanger comprises the burn line fuel-oil cooler and the
recirculation fuel-oil cooler.
4. The thermal management system of claim 2, further comprising a
bypass valve disposed on the returning portion and configured to
adjustably control a flow of oil from the returning portion into at
least one of the cooling line and the bypass line.
5. The thermal management system of claim 4, wherein the bypass
valve comprises a thermal valve.
6. The thermal management system of claim 4, wherein the bypass
valve comprises an electromechanical valve.
7. The thermal management system of claim 4, further comprising a
third sensor, disposed on the recirculation line downstream of the
recirculation fuel-oil cooler.
8. The thermal management system of claim 7, wherein at least one
of the first sensor, the second sensor, and the third sensor is in
communication with a controller.
9. The thermal management system of claim 8, wherein the controller
comprises a full authority digital engine control system.
10. The thermal management system of claim 7, wherein an integrated
bypass heat exchanger comprises the burn line fuel-oil cooler, the
recirculation fuel-oil cooler, the bypass valve, the bypass line,
and the cooling line.
11. The thermal management system of claim 10, wherein at least one
of the burn line fuel-oil cooler and the recirculation fuel-oil
cooler comprises a tubular heat exchanger.
12. A method of transferring heat in a thermal management system,
comprising: circulating a volume of fuel in a fuel circuit,
comprising a burn line and a recirculation line; circulating a
volume of oil in an oil circuit, comprising a sending portion and a
returning portion; transferring heat from the volume of oil to the
volume of fuel in a burn line fuel-oil cooler coupled to the burn
line; dividing the volume of fuel, such that a first portion of
fuel is communicated through a fuel throttle valve to a combustion
section and a second portion of fuel is communicated through the
fuel throttle valve and into the recirculation line; transferring
heat from the volume of oil to the second portion of fuel in a
recirculation fuel-oil cooler coupled to the recirculation line and
the returning portion; transferring heat from the second portion of
fuel to air in an air-fuel cooler coupled to the recirculation
line; determining, by a controller, an actual fuel temperature at a
third location; comparing, by the controller, the actual fuel
temperature to a threshold fuel recirculation temperature; and
adjusting, by the controller, a bypass valve in response to the
actual fuel temperature exceeding the threshold fuel recirculation
temperature, wherein the bypass valve is disposed in the returning
portion, wherein adjusting the bypass valve comprises controlling a
flow of the volume of oil from the returning portion to at least
one of: a cooling line, coupled to, and configured to carry oil
through, the recirculation fuel-oil cooler towards a burn line
fuel-oil cooler; and a bypass line, configured to carry oil towards
the burn line fuel-oil cooler, substantially in parallel with the
cooling line, and externally of the recirculation fuel-oil
cooler.
13. The method of claim 12, further comprising: transferring the
air externally from the thermal management system.
14. The method of claim 12, further comprising: determining, by a
controller, at least one of an actual oil temperature at a first
location and a second actual fuel temperature at a second location;
comparing, by the controller, at least one of the actual oil
temperature to a threshold oil temperature and the second actual
fuel temperature to a threshold fuel burn temperature; and
adjusting, by the controller, the fuel throttle valve in response
to at least one of the actual oil temperature exceeding the
threshold oil temperature and the second actual fuel temperature
exceeding the threshold fuel burn temperature.
15. The method of claim 14, wherein at least one of the actual oil
temperature and the second actual fuel temperature is derived by
the controller.
16. The method of claim 12, wherein the actual fuel temperature is
derived by the controller.
Description
FIELD OF THE DISCLOSURE
The present disclosure relates to thermal management systems for
gas turbine engines, and more particularly, to thermal management
systems utilizing a fuel recirculation circuit.
BACKGROUND OF THE DISCLOSURE
Gas turbine engines typically include at least a compressor
section, a combustor section, and a turbine section, disposed about
an axial centerline and arranged in flow series with an upstream
inlet at the compressor section and a downstream exhaust at the
turbine section. As compressed air passes from the compressor
section to the combustor section, it is mixed with fuel and burned.
As hot combustion gases expand, they are converted to work by the
turbine section, supplying power to the engine and other engine
loads.
The heat generated by a gas turbine engine may be managed by a
thermal management system. Thermal management systems may utilize
engine fluids such as fuel and oil to cool the engine by
transferring excess engine heat overboard. Above certain
temperature limits, engine oil may undergo coking and fuel may
undergo lacquering. Such oil and fuel temperature limits may limit
the heat sink capacity of thermal management systems.
SUMMARY OF THE DISCLOSURE
In various embodiments, the present disclosure provides thermal
management systems utilizing fuel recirculation and a recirculation
fuel-oil cooler. In various embodiments, a thermal management
system may increase heat sink capacity, decrease fuel recirculation
volume and/or flow rate, and/or maintain engine fluids within
temperature limits. For example, in various embodiments, a thermal
management system comprises an oil circuit, a fuel circuit,
comprising a burn line and a recirculation line, and a burn line
fuel-oil cooler. The thermal management system further comprises a
recirculation fuel-oil cooler, coupled to the recirculation line
and the oil circuit, and an air-fuel cooler coupled to the
recirculation line. In various embodiments, the thermal management
system may further comprise a fuel throttle valve. In various
embodiments, the thermal management system may further comprise at
least one sensor and/or a controller in communication with the
sensor. In various embodiments, the oil circuit may comprise a
bypass valve, bypass line, and cooling line. In various
embodiments, the thermal management system may comprise an
integrated heat exchanger.
In various embodiments, the present disclosure provides methods for
transferring heat in a thermal management system comprising
circulating a volume of fuel in a fuel circuit and circulating a
volume of oil in an oil circuit. The methods may further comprise
transferring heat from the volume of oil to the volume of fuel and
dividing the volume of fuel such that a first portion of fuel is
communicated to a combustion section and a second portion of fuel
is communicated into a recirculation line. The methods may further
comprise transferring heat from the volume of oil to the second
portion of fuel in a recirculation fuel-oil cooler and transferring
heat from the second portion of fuel to air. In various
embodiments, methods may further comprise transferring air
externally from the thermal management system. In various
embodiments, the methods may further comprise determining, by a
controller, a fuel temperature and/or an oil temperature, comparing
the fuel temperature and/or an oil temperature to a threshold
temperature, and adjusting the flow rate or volume of fuel and/or
oil in a thermal management system.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further
understanding of the present disclosure and are incorporated in,
and constitute a part of, this specification, illustrate various
embodiments, and together with the description, serve to explain
the principles of the disclosure.
FIG. 1 illustrates a schematic cross-section view of a gas turbine
engine in accordance with various embodiments;
FIG. 2a illustrates a schematic diagram of a thermal management
system in accordance with various embodiments;
FIG. 2b illustrates a schematic diagram of another thermal
management system in accordance with various embodiments;
FIG. 3a illustrates a schematic diagram of yet another thermal
management system in accordance with various embodiments;
FIG. 3b illustrates a schematic diagram of yet another thermal
management system in accordance with various embodiments; and
FIG. 4 illustrates a method of transferring heat in a thermal
management system in accordance with various embodiments.
DETAILED DESCRIPTION
The detailed description of various embodiments herein makes
reference to the accompanying drawings, which show various
embodiments by way of illustration. While these various embodiments
are described in sufficient detail to enable those skilled in the
art to practice the disclosure, it should be understood that other
embodiments may be realized and that logical, chemical, and
mechanical changes may be made without departing from the spirit
and scope of the disclosure. Thus, the detailed description herein
is presented for purposes of illustration only and not of
limitation.
For example, the steps recited in any of the method or process
descriptions may be executed in any order and are not necessarily
limited to the order presented. Furthermore, any reference to
singular includes plural embodiments, and any reference to more
than one component or step may include a singular embodiment or
step. Also, any reference to attached, fixed, connected, or the
like may include permanent, removable, temporary, partial, full,
and/or any other possible attachment option. Additionally, any
reference to without contact (or similar phrases) may also include
reduced contact or minimal contact.
For example, in the context of the present disclosure, methods and
devices may find particular use in connection with gas turbine
engines. However, various aspects of the disclosed embodiments may
be adapted for optimized performance in a variety of engines. As
such, numerous applications of the present disclosure may be
realized.
Referring to FIG. 1, a gas turbine engine 100 (such as a turbofan
gas turbine engine) is illustrated according to various
embodiments. Gas turbine engine 100 is disposed about axial
centerline axis of rotation 120. Gas turbine engine 100 may
comprise a fan 140, compressor sections 150 and 160, a combustion
section 180, and turbine sections 190, 191. The fan 140 may drive
air into compressor sections 150, 160, which further drive air
along a core flow path for compression and communication into the
combustion section 180. Air compressed in the compressor sections
150, 160 may be mixed with fuel and burned in combustion section
180 and expanded across the turbine sections 190, 191. The turbine
sections 190, 191 may include high pressure rotors 192 and low
pressure rotors 194, which rotate in response to the expansion. The
turbine sections 190, 191 may comprise alternating rows of rotary
airfoils or blades 196 and static airfoils or vanes 198. Cooling
air may be supplied to the turbine sections 190, 191 from the
compressor sections 150, 160. A plurality of bearings 115 may
support spools in the gas turbine engine 100. FIG. 1 provides a
general understanding of the sections in a gas turbine engine, and
is not intended to limit the disclosure. The present disclosure may
extend to all types of applications and to all types of turbine
engines, including turbofan engines, turboprop engines, and
turbojet engines.
Multiple sections of the gas turbine engine 100 generate heat
during engine operation, including the fan 140, the compressor
sections 150, 160, the combustion section 180, the turbine sections
190, 191, and mechanical components such as bearings 115 and
gearboxes (not shown). The heat may be carried by fluids that are
communicated throughout these and other portions of the engine 100.
For example, fuel and oil may be circulated throughout the gas
turbine engine 100 and carry a portion of the heat generated during
engine operation.
A gas turbine engine may further comprise a thermal management
system. Thermal management systems may utilize engine oil and/or
fuel to transfer heat from various portions of the engine to other
portions of the engine or areas external to the engine. For
example, an oil circulation system and a fuel circulation system
may have primary functions exclusive of their functions in the
thermal management system. For example, oil may function primarily
as a lubricant of various engine components (i.e., oil's primary
function); fuel may function primarily as an energy source (i.e.,
fuel's primary function).
The oil and fuel circulation systems may carry oil and fuel to
various portions of the engine to operate as heat sinks in a
thermal management system. However, the heat sink capacity of the
thermal management system may be limited by temperature limits
related to oil's primary function and/or fuel's primary function.
As used herein, heat sink capacity may be understood to be a
quantity of heat per unit of time capable of being absorbed and/or
dissipated by the thermal management system.
In various embodiments, a thermal management system may comprise a
fuel circuit and an oil circuit. The thermal management system may
be configured to circulate fuel in the fuel circuit and to
circulate oil in the oil circuit. In various embodiments, the
thermal management system may be configured such that heat is
transferred from the engine to oil, heat is transferred from the
oil to fuel, heat is transferred from the fuel to air, and air is
transferred externally from the engine or externally from the
thermal management system.
In various embodiments, heat may be transferred in at least one
heat exchanger. Various heat exchangers may be incorporated into
the thermal management system including, without limitation, gas to
liquid heat exchangers and liquid to liquid heat exchangers. Gas to
liquid heat exchangers may be configured to heat or cool liquid by
exposing it to gas having a different temperature than the liquid.
In various embodiments, liquids carrying engine heat may be cooled
by exposure to external engine air, air bled from various portions
of the engine ("bleed air"), or any other source of air lower in
temperature than the heat-carrying liquid. In various embodiments,
liquids may be heated by exposure to external engine air, bleed
air, or any other source of air higher in temperature than the
liquid. Liquid to liquid heat exchangers may be configured to heat
or cool a first liquid by exposing it to a second liquid having a
different temperature than the first liquid.
In various embodiments, thermal management system 200 may comprise
at least one heat exchanger. In various embodiments, the heat
exchanger may comprise a fuel-oil cooler and/or an air-fuel cooler.
In various embodiments, thermal management system 200 may comprise
a burn line fuel-oil cooler 230, a recirculation line fuel-oil
cooler 240, and an air-fuel cooler 250. In various embodiments,
burn line fuel-oil cooler 230 and recirculation line fuel-oil
cooler 240 may be configured to cool oil by exposing it to fuel
having a lower temperature than the oil. Such exposure may occur
without combining, mixing, or contaminating the oil with the fuel.
Stated another way, oil and fuel may come into thermal contact
without coming into physical contact in burn line fuel-oil cooler
230 and recirculation line fuel-oil cooler 240. In various
embodiments, air-fuel cooler 250 may be configured to cool fuel by
exposing it to air having a lower temperature than the fuel. Such
exposure may occur without combining, mixing, or contaminating the
fuel with the air. Stated another way, fuel and air may come into
thermal contact without coming into physical contact in air-fuel
cooler 250.
In various embodiments, the fuel circuit may comprise a burn line
210 and a fuel recirculation line 212. Burn line 210 may be
disposed between an aircraft fuel tank 214 and the combustion
section 180 of an engine. Burn line 210 may be configured to carry
fuel from aircraft fuel tank 214 to combustion section 180. In
various embodiments, recirculation line 212 may be in in fluid
communication with burn line 210 and disposed between burn line 210
and aircraft fuel tank 214. Recirculation line 212 may be
configured to carry fuel from burn line 210 back to fuel tank 214,
thereby creating a circuit.
In various embodiments, oil circuit 220 may be configured to
circulate oil between thermal management system 200 and an engine
lube system 260. In various embodiments, oil circuit 220 may
comprise a sending portion and a returning portion. The sending
portion may be configured to carry oil from burn line fuel-oil
cooler 230 to engine lube system 260. The returning portion may be
configured to carry oil from engine lube system 260 to burn line
fuel-oil cooler 230. In various embodiments, engine lube system 260
may generate heat that is transferred to oil circulating in oil
circuit 220.
In various embodiments, heat may be transferred by burn line
fuel-oil cooler 230 from oil circulating in oil circuit 220 to fuel
being carried through burn line 210. In various embodiments, burn
line fuel-oil cooler 230 may be disposed on, and coupled to burn
line 210 and oil circuit 220. In various embodiments, burn line
fuel-oil cooler 230 may comprise a tubular heat exchanger. However,
burn line fuel-oil cooler 230 may comprise any suitable heat
exchanger, such as a plate heat exchanger, a tube and shell heat
exchanger, a plate-fin heat exchanger, microchannel heat exchanger,
and the like.
In various embodiments, thermal management system 200 may further
comprise a fuel throttle valve 216 disposed on, and coupled to,
burn line 210 and recirculation line 212. In various embodiments,
fuel throttle valve 216 may be disposed downstream of burn line
fuel-oil cooler 230 on burn line 210. In various embodiments, fuel
throttle valve 216 may be configured to adjustably control the flow
of fuel from burn line 210 to recirculation line 212. For example,
in various embodiments, in response to the fuel throttle valve
being in a closed position, communication of fuel into
recirculation line 212 may be prevented. For example, in various
embodiments, in response to the fuel throttle valve being in a
partially open position, a first portion of fuel may be
communicated through burn line 210 to combustion portion 180, and a
second portion of fuel may be communicated through recirculation
line 212 to aircraft fuel tank 214.
In various embodiments, heat may be transferred by recirculation
fuel-oil cooler 240 from oil circulating in the returning portion
to fuel circulating in recirculation line 240. In various
embodiments, recirculation fuel-oil cooler 240 may be disposed on,
and coupled to recirculation line 212 and returning portion of oil
circuit 220. In various embodiments, recirculation fuel-oil cooler
240 may comprise a tubular heat exchanger. However, recirculation
fuel-oil cooler 240 may comprise any suitable heat exchanger, such
as a plate heat exchanger, a tube and shell heat exchanger, a
plate-fin heat exchanger, microchannel heat exchanger, and the
like.
In various embodiments, heat may be transferred by air-fuel cooler
250 from fuel circulating in recirculation line 240 to air. In
various embodiments, air-fuel cooler 250 may be disposed on and
coupled to recirculation line 212. In various embodiments, air-fuel
cooler 250 may comprise an airframe mounted heat exchanger.
However, air-fuel cooler 250 may comprise any suitable heat
exchanger.
In various embodiments, transferring heat from oil circulating in
the returning portion to fuel circulating in recirculation line 240
upstream of air-fuel cooler 250 may increase the heat sink capacity
of thermal management system 200. In various embodiments,
transferring heat from oil circulating in the returning portion to
fuel circulating in recirculation line 240 upstream of air-fuel
cooler 250 may decrease the volume and/or flow rate of fuel
communicated into recirculation line 212.
In various embodiments, and with reference to FIG. 2b, thermal
management system 200 may comprise an integrated fuel-oil cooler
280. In various embodiments, integrated fuel-oil cooler 280 may
comprise a burn line fuel-oil cooler 230 and a recirculation
fuel-oil cooler 240, as previously described.
In various embodiments and with reference to FIGS. 2a and 2b,
thermal management system 200 may further comprise at least one
sensor. In various embodiments, the sensor may comprise a
temperature sensor. In various embodiments, the sensor may comprise
a flow sensor and/or a flow meter. In various embodiments, thermal
management system 200 may further comprise a first sensor 202
disposed at a first location. In various embodiments, first sensor
202 may be disposed on and coupled to oil circuit 220. In various
embodiments, the first location may be on oil circuit 220
downstream of burn line fuel-oil cooler 230 and upstream of engine
lube system 260. In various embodiments, thermal management system
200 may further comprise a second sensor 204 disposed at a second
location. In various embodiments, second sensor 204 may be disposed
on and coupled to burn line 210. In various embodiments, the second
location may be on burn line 210 downstream of burn line fuel-oil
cooler 230. In various embodiments, the second location may be on
burn line 210 downstream of burn line fuel-oil cooler 230 and fuel
throttle valve 216.
In various embodiments, at least one of first sensor 202 and second
sensor 204 may be coupled to, and/or in communication with, a
controller 270. In various embodiments, controller 270 may comprise
a full authority digital engine control ("FADEC") system.
Controller 270 may comprise a processor configured to implement
various logical operations in response to execution of
instructions, for example, instructions stored on a non-transitory,
tangible, computer-readable medium.
As used herein, the term "non-transitory" is to be understood to
remove only propagating transitory signals per se from the claim
scope and does not relinquish rights to all standard
computer-readable media that are not only propagating transitory
signals per se. Stated another way, the meaning of the term
"non-transitory computer-readable medium" and "non-transitory
computer-readable storage medium" should be construed to exclude
only those types of transitory computer-readable media which were
found in In Re Nuijten to fall outside the scope of patentable
subject matter under 35 U.S.C. .sctn. 101. In various embodiments,
the processor may be configured to implement algorithms to derive,
calculate, and/or determine the temperature of fuel and/or oil in
response to receiving, from at least one of first sensor 202 and
second sensor 204, a temperature and/or flow rate measurement.
In various embodiments, thermal management system 200 may be
configured to maintain a temperature of fuel at or below a maximum
desired fuel temperature by increasing a rate of fuel flow. In
various embodiments, the maximum desired fuel temperature may be
predetermined. In various embodiments, a threshold fuel temperature
may be predetermined and may comprise a temperature lower than the
maximum desired fuel temperature. In various embodiments, the
threshold fuel temperature may comprise a temperature at which the
rate of fuel flow in the fuel circuit is increased in order to
prevent fuel from reaching a temperature at or exceeding the
maximum desired fuel temperature.
In various embodiments, thermal management system 200 may be
configured to maintain a temperature of oil at or below a maximum
desired oil temperature by increasing a rate of fuel flow. In
various embodiments, the maximum desired oil temperature may be
predetermined. In various embodiments, a threshold oil temperature
may be predetermined and may comprise a temperature lower than the
maximum desired oil temperature. In various embodiments, the
threshold oil temperature may comprise a temperature at which the
rate of fuel flow in the fuel circuit is increased in order to
prevent oil from reaching a temperature at or exceeding the maximum
desired oil temperature.
In various embodiments and with reference to FIG. 3a, thermal
management system 300 may comprise a bypass system configured to
prevent fuel from reaching a temperature at or exceeding the
maximum desired fuel temperature. In various embodiments, the
returning portion of oil circuit 220 may comprise a bypass valve
326, a bypass line 324, and a cooling line 322. In various
embodiments, bypass valve 326 may be disposed on, and coupled to,
returning portion of oil circuit 220, bypass line 324, and cooling
line 322. In various embodiments, bypass valve 326 may be
configured to adjustably control the flow of oil from returning
portion to at least one of cooling line 322 and bypass line
324.
In various embodiments, bypass valve 326 may comprise a thermal
valve such as a wax thermostatic element or a bimetallic
thermostatic element. In various embodiments, bypass valve 326 may
comprise an electromechanical valve such as a solenoid operated
valve. However, bypass valve 326 may comprise any valve suitable
for use in thermal management system 300. In various embodiments,
controller 270 may be in communication with bypass valve 326 and
may command bypass valve 326 to open and/or close.
In various embodiments, cooling line 322 may be in fluid
communication with oil circuit 220. In various embodiments, cooling
line 322 may be disposed between bypass valve 326 and burn line
fuel-oil cooler 230. In various embodiments, cooling line 322 may
be configured to communicate oil from bypass valve 326, through
recirculation fuel-oil cooler 240, and towards burn line fuel-oil
cooler 230.
In various embodiments, bypass line 324 may be in fluid
communication with oil circuit 220. In various embodiments, bypass
line 324 may be disposed between bypass valve 326 and burn line
fuel-oil cooler 230. In various embodiments, bypass line 324 may be
configured to communicate oil from bypass valve 326, towards burn
line fuel-oil cooler 230, without communicating oil through
recirculation fuel-oil cooler 240. Stated differently, in various
embodiments, bypass line 324 may communicate oil substantially in
parallel with cooling line 322, and externally of recirculation
fuel-oil cooler 240. As used herein, the term parallel should be
understood to describe a first flow path which shares a starting
and ending terminus with a second flow path, but through which flow
is mutually exclusive of flow through the second flow path.
In various embodiments, bypass line 324 and cooling line 322 may
integrate, reunite, and/or regain mutual fluid communication in the
returning portion downstream of recirculation fuel-oil cooler 240
and upstream of burn line fuel-oil cooler 230.
In various embodiments, communication of oil through bypass line
324 may increase the heat sink capacity of thermal management
system 300. In various embodiments, communication of oil through
bypass line 324 may maintain oil and/or fuel temperature within
predetermined limits.
In various embodiments, and with reference to FIG. 3b, thermal
management system 300 may comprise an integrated bypass fuel-oil
cooler 380. In various embodiments, integrated bypass fuel-oil
cooler 380 may comprise a burn line fuel-oil cooler 230, a
recirculation fuel-oil cooler 240, a bypass valve 326, a bypass
line 324, and a cooling line 322, as previously described.
In various embodiments, and with reference to FIGS. 3a and 3b,
thermal management system may further comprise a third sensor 306
disposed at a third location. In various embodiments, third sensor
306 may comprise a temperature sensor. In various embodiments,
third sensor 306 may comprise a flow sensor and/or a flow meter. In
various embodiments, third sensor 306 may be disposed on and
coupled to recirculation line 212. In various embodiments, the
third location may be on recirculation line 212 downstream of
recirculation fuel-oil cooler 240 and upstream of air-fuel cooler
250.
In various embodiments, third sensor 306 may be coupled to, and/or
in communication with, controller 270. In various embodiments,
controller 270 may comprise a processor configured to implement
various logical operations in response to execution of
instructions, for example, instructions stored on a non-transitory,
tangible, computer-readable medium. In various embodiments, the
processor may be configured to implement algorithms to derive,
calculate, and/or determine the temperature of fuel in response to
receiving, from third sensor 306, a temperature and/or flow rate
measurement. In various embodiments, thermal management system 300
may be configured to maintain a temperature of fuel at or below a
maximum desired fuel temperature by communicating oil through
bypass line 324.
In various embodiments and with reference to FIG. 4, a method of
transferring heat in a thermal management system comprises
circulating a volume of fuel in the fuel circuit (Step 401), and
circulating a volume of oil in in oil circuit 220 (Step 402). In
various embodiments, the fuel circuit may comprise a burn line 210
and a recirculation line 212. In various embodiments, oil circuit
220 may comprise a sending portion and a returning portion. Oil and
fuel may be communicated to burn line fuel-oil cooler 230. In
various embodiments, method 400 may further comprise transferring
heat from the volume of oil to the volume of heat in burn line
fuel-oil cooler 230 (Step 403).
In various embodiments, method 400 may further comprise dividing
the volume of fuel (Step 404). The volume of fuel may be divided at
fuel throttle valve 216 into a first portion of fuel and a second
portion of fuel. In various embodiments, the first portion of fuel
may be communicated into recirculation line 212 and the second
portion may be communicated towards a combustion section 180. In
various embodiments, a position of fuel throttle valve 216 may
determine the quantity of fuel communicated into recirculation line
212 and the quantity of fuel communicated towards combustion
section 180.
Oil and the second portion of fuel may be communicated to
recirculation fuel-oil cooler 240. In various embodiments, method
400 may further comprise transferring heat from the volume of oil
to the second portion of fuel in recirculation fuel-oil cooler 240
(Step 405). The second portion of fuel may be communicated to
air-fuel cooler 250. In various embodiments, method 400 may further
comprise transferring heat from the second portion of fuel to air
in air-fuel cooler 250 (Step 406). In various embodiments, method
400 may further comprise transferring air externally from the
thermal management system (Step 407).
In various embodiments, method 400 may further comprise adjusting
the volume and/or flow rate of fuel and/or oil in order to maintain
fuel temperature and oil temperature within predetermined limits.
In various embodiments, method 400 may further comprise receiving,
by a controller, at least one of an actual oil temperature at the
first location and an actual combustion fuel temperature at the
second location (Step 408). The actual oil temperature may comprise
a temperature of oil at the first location at a first time. The
actual combustion fuel temperature may comprise a temperature of
fuel at the second location at a second time. The first time may be
before, simultaneous with, or after the second time.
In various embodiments, method 400 may further comprise comparing,
by the controller, at least one of the actual oil temperature to a
threshold oil temperature and the actual combustion fuel
temperature to a threshold fuel temperature (Step 409). In various
embodiments, controller 270 may derive the actual combustion fuel
temperature and/or the actual oil temperature using algorithms.
In various embodiments, method 400 may further comprise adjusting
fuel throttle valve 216 (Step 410). In various embodiments, fuel
throttle valve 216 may adjust in response to a command from
controller 270. In various embodiments, fuel throttle valve 216 may
adjust such that the volume and/or flow rate of fuel being
communicated into recirculation line 212 is increased in response
to at least one of the actual oil temperature exceeding the
threshold oil temperature and the actual fuel temperature exceeding
the threshold fuel temperature. In various embodiments, fuel
throttle valve 216 may adjust such that the volume and/or flow rate
of fuel being communicated through burn line fuel-oil cooler 230 is
increased in response to at least one of the actual oil temperature
exceeding the threshold oil temperature and the actual fuel
temperature exceeding the threshold fuel temperature.
In various embodiments, method 400 may further comprise receiving,
by a controller, an actual recirculation fuel temperature at the
third location (Step 411). The actual recirculation fuel
temperature may comprise a temperature of fuel at the third
location at a third time. The third time may be before,
simultaneous with, or after the first time and/or the second time.
[please make the descriptions of 408-410 different than
411-413].
In various embodiments, method 400 may further comprise comparing,
by the controller, the actual recirculation fuel temperature to a
threshold fuel temperature (Step 412). In various embodiments,
controller 270 may derive the actual recirculation fuel temperature
using algorithms.
In various embodiments, method 400 may further comprise adjusting
bypass valve 326 (Step 413). In various embodiments, bypass valve
326 may adjust in response to a command from controller 270. In
various embodiments, bypass valve 326 may adjust such that the
volume and/or flow rate of fuel being communicated into bypass line
324 is increased in response to the actual fuel recirculation
temperature exceeding the threshold fuel temperature.
Benefits, other advantages, and solutions to problems have been
described herein with regard to specific embodiments. Furthermore,
the connecting lines shown in the various figures contained herein
are intended to represent exemplary functional relationships and/or
physical couplings between the various elements. It should be noted
that many alternative or additional functional relationships or
physical connections may be present in a practical system. However,
the benefits, advantages, solutions to problems, and any elements
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as critical,
required, or essential features or elements of the disclosure. The
scope of the disclosure is accordingly to be limited by nothing
other than the appended claims, in which reference to an element in
the singular is not intended to mean "one and only one" unless
explicitly so stated, but rather "one or more." Moreover, where a
phrase similar to "at least one of A, B, or C" is used in the
claims, it is intended that the phrase be interpreted to mean that
A alone may be present in an embodiment, B alone may be present in
an embodiment, C alone may be present in an embodiment, or that any
combination of the elements A, B and C may be present in a single
embodiment; for example, A and B, A and C, B and C, or A and B and
C. Different cross-hatching is used throughout the figures to
denote different parts but not necessarily to denote the same or
different materials.
Devices and methods are provided herein. In the detailed
description herein, references to "one embodiment", "an
embodiment", "various embodiments", etc., indicate that the
embodiment described may include a particular feature, structure,
or characteristic, but every embodiment may not necessarily include
the particular feature, structure, or characteristic. Moreover,
such phrases are not necessarily referring to the same embodiment.
Further, when a particular feature, structure, or characteristic is
described in connection with an embodiment, it is submitted that it
is within the knowledge of one skilled in the art to affect such
feature, structure, or characteristic in connection with other
embodiments whether or not explicitly described. After reading the
description, it will be apparent to one skilled in the relevant
art(s) how to implement the disclosure in alternative
embodiments.
Furthermore, no element, component, or method step in the present
disclosure is intended to be dedicated to the public regardless of
whether the element, component, or method step is explicitly
recited in the claims. No claim element herein is to be construed
under the provisions of 35 U.S.C. 112(f) unless the element is
expressly recited using the phrase "means for." As used herein, the
terms "comprises", "comprising", or any other variation thereof,
are intended to cover a non-exclusive inclusion, such that a
process, method, article, or apparatus that comprises a list of
elements does not include only those elements but may include other
elements not expressly listed or inherent to such process, method,
article, or apparatus.
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